The starting point of the invention is an electric starter motor for internal combustion engines which motor comprises a drive shaft for rotatably supporting an armature and a commutator. The drive shaft itself is supported for rotation in drive and commutator bearings of which the latter is covered with a cap. Such a starter motor is disclosed in DE-OS 31 31 148. In this starter motor lubricant leaks into the cover cap fitted relatively tightly over the parts of an armature longitudinal play compensator and of a bearing extension of the commutator end shield, and screwed the end face of the commutator end shield. In this arrangement it is a disadvantage that the lubricant is not held sufficiently leaktightly in the cover cap. The lubricant intended to lubricate the drive shaft support point in a plain bearing inserted in the bearing extension can to a great extent escape between the bearing extension and the cover cap. Lubricant consumption is therefore undesirably high. In addition, undesirable noise is repeatedly caused through collision between the cover cap and an inserted disc provided with an U-shaped opening. Bearing damage through lack of lubricant.